http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
인슐린 비의존형 당뇨병 환자에서 혈장 Endothelin-1농도의 변화
신양수,조희충,김원식,국기용,김용화,정종훈,문철웅,배학연,양성훈 朝鮮大學校 附設 醫學硏究所 1992 The Medical Journal of Chosun University Vol.17 No.2
Endothelin(ET) is a 21-residue peptide originally isolated from the cultured porcine endothelial cells. There are at least three genes for endothelin:endothelin-1(ET-1), endothelin-2(ET-2), and endothelin-3(ET-3). Endothelins are present in various human biological fluids including plasma, urine, breast milk, and saliva and have been found elevated plasma ET concentrations in patients with diabetes mellitus, Patients undergoing maintenance hemodialysis due to chronic renal failure, patients with acute myocardial infarction, and patients with subarachnoid hemorrhage. Endothelial cell damage is suspected to occur in diabetic patients and may be one important cause of angiopathy, a major complication in diabetes mellitus. The elevation of ET in diabetic patients may be a marker of, and further exacerbate, their vascular disease. We measured the levels of ET-1 in plasma of 50 patients with non-insulin dependent diabetes mellitus(NIDDM) and 25 normal subjects by radioimmunoassay. The plasma ET-1 concentration (mean±S.D.) in NIDDM was 6.461 A2.510 f㏖/ ㎖, and was significantly higher than in normal subjects (4.567±1.155f㏖/㎖) (P<0.05). The plasma ET-1 concentration (mean±S.D.) in diabetic retinopathy group( 7.15±2.454 f㏖/ml) was significantly elevated than those in otherwise uncomplicated groups (5.348±2.390 f㏖/㎖)(P<0.01). The correlation between any clinical parameters and plasma ET-1 levels in NIDDM was not significant, In conclusion, this study suggest that the elevated levels of ET-1 in diabetic patients may be play a important role in the pathogenesis of diabetic complications.
Yang, Chul Hak,Kim, Young Ah,Kim, Hyun Kyung 생화학분자생물학회 1999 BMB Reports Vol.31 No.1
To purify the geranylgeranyl protein transferase type I (GGPT-I) efficiently, a gene expression system using the pGEX-4T-1 vector was constructed. The cal 1 gene, encoding the β subunit of GGPT-I, was subcloned into the pGEX-4T-1 vector and co-transformed into E. coli cells harboring the ram2 gene, the α subunit gene of GGPT-I. GGPT-I was highly expressed as a fusion protein with glutathione S-transferase (GST) in E. coli, purified to homogeneity by glutathione-agarose affinity chromatography, and the GST moiety was excised by thrombin treatment. The purified yeast GGPT-I showed a dose-dependent increase in the transferase activity, and its apparent K_m value for an undecapeptide fused with GST (GST-PEP) was 0.66μM and the apparent K_m value for geranylgeranyl pyrophosphate (GGPP) was 0.071 μM.
Quantitative Assay for the Binding of Jun-Fos Dimer and Activator Protein-1 Site
Yang, Chul Hak,Jun, Gyo,Lee, Dug Keun,Lee, Sang Kyou,Park, Se Yeon,Hahm, Eun Ryeong 생화학분자생물학회 1998 BMB Reports Vol.32 No.6
The Jun and Fos families of eukaryotic transcription factors form heterodimers capable of binding to their cognate DNA enhancer elements. We are interested in searching for inhibitors or antagonists of the binding of the Jun-Fos heterodimer to the activator protein-1 (AP-1) site. The basic-region leucine zipper (bZIP) domain of c-Fos was expressed as a fusion protein with glutathione S-transferase, and allowed to form a heterodimer with the bZIP domain of c-Jun. The heterodimer was bound to glutathione-agarose, to which were added radiolabeled AP-1 nucleotides. After thorough washing, the gel-bound radioactivity was counted. The assay is faster than the conventional electrophoretic mobility shift assay because the gel electrophoresis step and the autoradiography step are eliminated. Moreover, the assay is very sensitive, allowing the detection of picomolar quantities of nucleotides, and is not affected by up to 50% dimethylsulfoxide, a solvent for hydrophobic inhibitors. Curcumin and dihydroguaiaretic acid, recently known inhibitors of Jun-Fos-DNA complex formation, were applied to this Jun-GST-fused Fos system and revealed to decrease the dimer-DNA binding.
Yang, Chul Hak,Park, Se Yeon,Kwon, Hae Young,Lee, Dug Keun,Kim, Kyoung Su 생화학분자생물학회 2002 BMB Reports Vol.34 No.1
The Fos-Jun heterodimers are part of the regulatory network of gene expression and nuclear proteins encoded by proto-oncogenes. The activation of Fos-Jun is important in the transmission of the tumor-promoting signal from the extracellular environment to the nuclear transcription mechanism. To search for the inhibitors of the Fos-Jun DNA complex formation, several natural products were screened and water-soluble paeoniflorin reduced the binding activity of the Fos-Jun heterodimer. This active compound was purified by silica gel column chromatography and HPLC. The electrophoresis mobility shift assay and reverse-phase HPLC test showed that paeoniflorin reduced the AP-1 function. The cytotoxic effect of paeoniflorin was observed in HL-60. These results indicate that paeoniflorin blocks the Fos-Jun heterodirner-binding site of the AP-1 DNA and it also has cytotoxic effects on human leukemia cell lines.
Quantitative Assay for the Binding of Jun-Fos Dimer and Activator Protein-1 Site
Yang,Chul-Hak,Jun,Gyo,Hahm,Eun-Ryeong,Lee,Sangkyou,Park,Seyeon,Lee,Dug-Keun The Korea Science and Technology Center 1999 BMB Reports Vol.32 No.6
The Jun and Fos families of eukaryotic transcription factors form heterodimers capable of binding to their cognate DNA enhancer elements. We are interested in searching for inhibitors or antagonists of the binding of the Jun-Fos heterodimer to the activator protein-1 (AP-1) site. The basic-region leucine zipper (bZIP) domain of c-Fos was expressed as a fusion protein with glutathione S-transferase, and allowed to form a heterodimer with the bZIP domain of c-Jun. The heterodimer was bound to glutathione-agarose, to which were added radiolabeled AP-1 uncleotides. After thorough washing, the gel-bound radioactivity was counted. The assay is faster than the coventional electrophoretic mobility shift assay because the gel electrophoresis step and the autoradiography step are eliminated. Moreover, the assay is very sensitive, allowing the detection of picomolar quantities of nucleotides, and is not affected by up to 50% dimethylsulfoxide, a solvent for hydrophobic inhibitors. Curcumin and dihydroguaiaretic acid, recently known inhibitors of Jun-Fos-DNA complex formation, were applied to this Jun-GST-fused Fos system and revealed to decrease the dimer-DNA binding.
Chemical Modification Studies of Yeast Farnesyl Protein Transferase
Yang, Chul Hak,Sohn, Seung Wan,Jun, Gyo 생화학분자생물학회 1998 BMB Reports Vol.30 No.4
Phenylglyoxal, diethyl pyrocarbonate (DEPC), and 1-cyclohexyl-3-[2-morpholinoethyl]-carbodiimide metho-p-toluenesulfonate (CMC) are modifying reagents specific for arginine, histidine, and aspartate or glutamate, respectively. They were found to inactivate S. cerevisiae farnesyl protein transferase (FPTase). The peptide substrate protected the enzyme against inactivation by CMC. and the other substrate farnesyl pyrophosphate showed protection against inactivation by phenylglyoxal. while neither of the two substrates protected the enzyme against DEPC inactivation. These results suggest the presence of aspartate/glutamate, arginine and histidine residues at the active site of this enzyme.
Purification and Characterization of Farnesyl Protein Transferase from Bovine Testis
Yang, Chul Hak,Baik, Young Jin,Ryu, Kwon Yul 생화학분자생물학회 1977 BMB Reports Vol.28 No.3
Famesyl protein transferase involved in the first step of post-translational modification of p21^(ras) proteins transfers the famesyl moiety from famesyl pyrophosphate to a cysteine residue in p21^(ras) proteins. The enzyme was first purified 30,000-fold from bovine testis by use of 30∼50% ammonium sulfate fractionation, DEAE-Sephacel ion exchange chromatography, Sephacryl S-300 gel filtration chromatography, Sephacryl S-200 gel filtration chromatography, and hexapeptide (Lys-Lys-Cys-Val-Ile-Met) affinity chromatography. The molecular weight of the purified enzyme was estimated to be ∼100 kDa by gel filtration and SDS-polyacrylamide gels showed two closely spaced bands of ∼50 kDa protein. These indicate that the enryme consists of two nonidentical subunits, a and β, which have slightly different molecular weights. The enzyme was inhibited by hexapeptide (Lys-Lys-Cys-Val-Ile-Met), which acted as an alternative substrate that competed for famesylation. Kinetic analysis by measuring initial velocities showed that famesyl protein transferase is a very slow enzyme. EDTA-treated famesyl protein transferase showed little activity with Mg^(2+) or Zn^(2+) alone, but required both Mg^(2+) and Zn^(2+) for the catalytic activity.